The chapter explores the intricate relationship between sex, gender, science, and technology within STS, examining historical and contemporary intersections. Early STS studies, influenced by second-wave feminism, initially addressed gender inequalities in science and technology, emphasizing women’s underrepresentation. Over time, research expanded to encompass various ways sex and gender interact with these domains. One central theme is social constructivism, questioning Western science’s objectivity and universality. Researchers argue that science and technology aren’t value-neutral, reflecting societal norms and biases. Gender imbalances persist in science and technology jobs, influenced by stereotypes, bias, and limited role models. Work–life challenges, preference differences, and ability disparities contribute to the gender gap. The chapter delves into technology-gendering, examining how certain technologies, such as home appliances, crash dummies, and digital assistants, are associated with specific genders. These design choices either reinforce or challenge traditional gender norms. The discussion extends to gender’s impact on science communication, technological embodiment, and cyberspaces. Online spaces raise concerns about gendered harassment and cyberbullying. The passage also addresses gender imbalances in tech entrepreneurship and leadership, emphasizing women’s underrepresentation in startup ventures. The intersection of gender and AI reveals biases in algorithmic decision-making.